package com.lbc.callable;

import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.FutureTask;

public class CallableTest {
    public static void main(String[] args) throws ExecutionException, InterruptedException {
//        new Thread(new Runnable()).start();
//        new Thread(new FutureTask<V>()).start();
//        new Thread(new FutureTask<V>( Callable )).start();
        new Thread().start();  //  怎么启动Callable

        MyThread thread = new MyThread();
        FutureTask futureTask = new FutureTask(thread);  //  适配类

        new Thread(futureTask, "A").start();
        new Thread(futureTask, "B").start();  //  问：此时会打印几个call?

        Integer o = (Integer) futureTask.get();  //  这个get 方法可能会产生阻塞！把他放到最后面
        //  或者使用异步通信来处理！
        System.out.println(o);
    }
}

class MyThread implements Callable<Integer> {

    @Override
    public Integer call() throws Exception {
        System.out.println("call");  //  答：1、一次，结果会被缓存，效率高  2、结果可能需要等待，会阻塞！
        //  耗时的操作
        return 1024;
    }
}